A mesh network may include a number of nodes, each in communication with one or more other nodes in the network. Each node includes a radio, typically capable of transmission and reception. In some example networks, communication may utilize radio frequency (RF) signals spread over a plurality of “channels,” with each channel defined over a particular range of frequencies.
It is possible that one channel may provide better reception than another channel. Accordingly, it may be advantageous for nodes in the network to sequentially tune one channel after another. This can be described as “channel hopping,” and may be performed according to a time schedule. Because of the time schedule, synchronization between nodes is very important.
A classical solution to synchronization involves broadcast of a beacon frame that contains a timestamp. Nodes hearing the beacon will synchronize their clocks. However, the classical solution utilizes considerable network resources since, for example, leaf nodes will propagate (i.e., rebroadcast) the beacon despite the fact that they have no child nodes.